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Cheap flights from Portland, Maine to London from $339

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Portland, Maine to London departing on 10/9. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Find the cheapest flights from Portland, Maine to London

Cheap round-trip flights

JetBlue Logo
2:17 pm - 8:45 pmPWM-LHR
25h 28m1 stop
JetBlue Logo
11:55 am - 10:01 pmLHR-PWM
15h 06m1 stop
$642JetBlue
Find Deal
mar., sep. 30 - mar., oct. 7
JetBlue Logo
2:17 pm - 8:45 pmPWM-LHR
25h 28m1 stop
JetBlue Logo
8:15 am - 10:02 pmLHR-PWM
18h 47m1 stop
$677JetBlue
Find Deal
vie., oct. 17 - vie., oct. 24
United Airlines Logo
3:45 pm - 7:15 amPWM-LHR
10h 30m1 stop
United Airlines Logo
8:40 am - 11:59 pmLHR-PWM
20h 19m2 stops
$732United Airlines
Find Deal
mié., oct. 1 - mié., oct. 8
United Airlines Logo
3:15 pm - 10:40 amPWM-LHR
14h 25m2 stops
United Airlines Logo
1:45 pm - 11:13 pmLHR-PWM
14h 28m2 stops
$737United Airlines
Find Deal
mar., sep. 30 - mar., oct. 7
Logo
8:00 am - 6:30 amPWM-LHR
17h 30m3 stops
Logo
2:05 pm - 11:13 pmLHR-PWM
14h 08m2 stops
$758
Find Deal
mar., sep. 30 - mar., oct. 7
Air Canada Logo
8:00 am - 6:30 amPWM-LHR
17h 30m3 stops
Air Canada Logo
8:30 am - 11:13 pmLHR-PWM
19h 43m3 stops
$764Air Canada
Find Deal
mar., sep. 30 - mar., oct. 7
Air Canada Logo
8:00 am - 6:30 amPWM-LHR
17h 30m3 stops
Air Canada Logo
8:30 am - 11:13 pmLHR-PWM
19h 43m3 stops
$814Air Canada
Find Deal
vie., oct. 17 - vie., oct. 24
Logo
2:38 pm - 8:50 amPWM-LHR
13h 12m1 stop
Logo
4:05 pm - 12:05 amLHR-PWM
13h 00m1 stop
$861
Find Deal
vie., oct. 10 - lun., oct. 20
Delta Logo
2:35 pm - 6:20 amPWM-LHR
10h 45m1 stop
Delta Logo
8:50 am - 11:51 pmLHR-PWM
20h 01m1 stop
$876Delta
Find Deal
mar., nov. 25 - dom., nov. 30
Delta Logo
2:38 pm - 10:30 amPWM-LHR
14h 52m2 stops
Delta Logo
9:20 am - 10:19 pmLHR-PWM
17h 59m1 stop
$881Delta
Find Deal
jue., oct. 9 - sáb., oct. 18

United Airlines flights from Portland, Maine to London Heathrow Airport

Our best United Airlines deals on Portland, Maine to London Heathrow Airport flight tickets
United Airlines
Oct 1
PWM3:45 pmPortland
10h 30m
1 stop
LHR7:15 amLondon Heathrow
Oct 8
LHR8:40 amLondon Heathrow
20h 19m
2 stops
PWM11:59 pmPortland
$732
Find similar
United Airlines
Sep 30
PWM3:15 pmPortland
14h 25m
2 stops
LHR10:40 amLondon Heathrow
Oct 7
LHR1:45 pmLondon Heathrow
14h 28m
2 stops
PWM11:13 pmPortland
$737
Find similar
United Airlines
Oct 17
PWM5:41 pmPortland
11h 29m
1 stop
LHR10:10 amLondon Heathrow
Oct 24
LHR7:30 amLondon Heathrow
14h 14m
2 stops
PWM4:44 pmPortland
$789
Find similar

Scandinavian Airlines flights from Portland, Maine to London Heathrow Airport

Our best Scandinavian Airlines deals on Portland, Maine to London Heathrow Airport flight tickets
Scandinavian Airlines
Oct 17
PWM6:50 amPortland
21h 45m
2 stops
LHR9:35 amLondon Heathrow
Oct 24
LHR7:05 amLondon Heathrow
22h 00m
2 stops
PWM12:05 amPortland
$775
Find similar
Scandinavian Airlines
Sep 13
PWM6:33 amPortland
22h 02m
2 stops
LHR9:35 amLondon Heathrow
Sep 20
LHR6:40 amLondon Heathrow
22h 54m
2 stops
PWM12:34 amPortland
$790
Find similar
Scandinavian Airlines
Dec 7
PWM2:35 pmPortland
22h 05m
2 stops
LHR5:40 pmLondon Heathrow
Dec 12
LHR7:30 pmLondon Heathrow
33h 21m
2 stops
PWM11:51 pmPortland
$966
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Portland, Maine to London Heathrow Airport that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated agosto 18, 2025.
Use the filters below to find and compare flights from Portland, Maine to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

PortlandLondon

PWM - LHR

PWMLHR

Portland

mar. 9/30

2:17 pm-8:45 pm

1 stop25h 28m

London Heathrow

mar. 10/7

11:55 am-10:01 pm

1 stop15h 06m

$642

PortlandLondon

PWM - LHR

PWMLHR

Portland

vie. 10/17

2:17 pm-8:45 pm

1 stop25h 28m

London Heathrow

vie. 10/24

8:15 am-10:02 pm

1 stop18h 47m

$677

PortlandLondon

PWM - LHR

PWMLHR

Portland

mié. 10/1

3:45 pm-7:15 am

1 stop10h 30m

London Heathrow

mié. 10/8

8:40 am-11:59 pm

2 stops20h 19m

$732

PortlandLondon

PWM - LHR

PWMLHR

Portland

mar. 9/30

3:15 pm-10:40 am

2 stops14h 25m

London Heathrow

mar. 10/7

1:45 pm-11:13 pm

2 stops14h 28m

$737

PortlandLondon

PWM - LHR

PWMLHR

Portland

mar. 9/30

8:00 am-6:30 am

3 stops17h 30m

London Heathrow

mar. 10/7

2:05 pm-11:13 pm

2 stops14h 08m

$758

PortlandLondon

PWM - LHR

PWMLHR

Portland

mar. 9/30

8:00 am-6:30 am

3 stops17h 30m

London Heathrow

mar. 10/7

8:30 am-11:13 pm

3 stops19h 43m

$764

PortlandLondon

PWM - LHR

PWMLHR

Portland

vie. 10/17

8:00 am-6:30 am

3 stops17h 30m

London Heathrow

vie. 10/24

8:30 am-11:13 pm

3 stops19h 43m

$814

PortlandLondon

PWM - LHR

PWMLHR

Portland

vie. 10/10

2:38 pm-8:50 am

1 stop13h 12m

London Heathrow

lun. 10/20

4:05 pm-12:05 am

1 stop13h 00m

$861

PortlandLondon

PWM - LHR

PWMLHR

Portland

mar. 11/25

2:35 pm-6:20 am

1 stop10h 45m

London Heathrow

dom. 11/30

8:50 am-11:51 pm

1 stop20h 01m

$876

PortlandLondon

PWM - LHR

PWMLHR

Portland

jue. 10/9

2:38 pm-10:30 am

2 stops14h 52m

London Heathrow

sáb. 10/18

9:20 am-10:19 pm

1 stop17h 59m

$881

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 16 resultsSorted by cheapest first
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See travel insights to London from

How to get the cheapest flight ticket from Portland, Maine to London Heathrow Airport

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the typical price of a round-trip flight between Portland, Maine and London Heathrow Airport?

What is the cheapest month to fly to London Heathrow Airport?

The month of April is, on average, the cheapest month to fly to London Heathrow Airport from Portland, Maine, with most prices found around $710. If you’re not able to fly to London Heathrow Airport in April, then May is your next best option. Flight prices from Portland, Maine to London Heathrow Airport during May average around $750.

What is the cheapest day to depart on your flight to London Heathrow Airport?

Our data shows that Sunday is the least expensive day to fly to London Heathrow Airport. Tickets to fly out on this day can be as low as $852. The most expensive day to fly to London Heathrow Airport is Wednesday, with ticket prices averaging around $1,003.

What is the cheapest time of day to depart on your flight to London Heathrow Airport?

According to our data, the cheapest time of day to fly to London Heathrow Airport is in the afternoon. momondo users have found flights departing from Portland, Maine to London Heathrow Airport in the afternoon for as low as $842. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights in the morning are often more expensive with an average ticket price of $931.

When to book flights from Portland, Maine to London Heathrow Airport

Are you open to changing your travel dates? Check out the ideal times to fly from Portland, Maine to London Heathrow Airport according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Portland, Maine to London Heathrow Airport (PWM to LHR) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Portland, Maine to London Heathrow Airport

Best Price Found

$339

Fastest flight time

10h 30m

Direct flights

None
The best one-way flight to London Heathrow Airport from Portland, Maine in the past 72 hours is $339. The best round-trip flight deal from Portland, Maine to London Heathrow Airport found on momondo in the last 72 hours is $642.
The fastest flight from Portland, Maine to London Heathrow Airport takes 10h 30m
There are no direct flights from Portland, Maine to London Heathrow Airport. Popular non-direct route for this connection is Portland Airport - London Heathrow Airport.
Search flight deals

  • How far is Portland to London Heathrow by plane?

    The distance between Portland and London Heathrow is about 3170.3 mi. In terms of flight time, this usually takes a little over 10h 30m.

  • When did momondo last update prices for flights from Portland Airport to London Heathrow Airport?

    Prices for flights from Portland Airport to London Heathrow Airport refresh daily.

  • How many operators does momondo search for flights from Portland Airport to London Heathrow Airport?

  • How old do you have to be to fly from Portland Airport to London Heathrow Airport?

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Portland Airport to London Heathrow Airport.

  • What documentation or ID do you need to fly to London Heathrow Airport?

    The necessary travel and health documents for your London Heathrow Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

  • What is the most popular airline from Portland, Maine to London Heathrow Airport?

Best airlines flying from Portland, Maine to London Heathrow Airport

Compare and see reviews for airlines that fly from Portland, Maine to London Heathrow Airport with momondo
Airline
Rating
Free Cancellation
Price
JetBluePriceFrom $586Free CancellationRating
7.2
2,915 reviews
Search JetBlue flights
United AirlinesPriceFrom $648Free CancellationRating
7.4
8,925 reviews
Search United Airlines flights
DeltaPriceFrom $825Free CancellationRating
8.0
7,981 reviews
Search Delta flights

Traveling to a place near London?

Book flights to London if you plan to visit one of these locations
Hounslow
Gatwick
Dover
Slough
Luton
Guildford
Milton Keynes
Dartford
Crawley
Hayes
Chelmsford
Stansted
Salisbury
Brentwood
Ilford
Swindon
Colchester
Folkestone
Stratford-upon-Avon
Watford

Why use momondo?

Why should I use momondo to find a flight deal from Portland to London?

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to London from Portland.

Can I find flights from Portland to London with flexible booking policies on momondo?

Yes. momondo enables you to select and highlight flights to London from Portland with this policy.

How can momondo help me find flights from Portland to London?

Once you have performed a search for Portland to London flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

I’m not ready to book a flight from Portland to London right now. Can momondo alert me if prices change?

If you are simply researching potential flights to London, momondo offers a useful price alert feature which will track prices for flights to London from Portland and alert you when they change.

An easier way to manage your London Heathrow Airport trip

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